Methods and devices for treating tissue

ABSTRACT

Device and method are provided for diagnosing and treating diseases and injuries to the spine by injecting drugs into the diseased or injured area. The device and method of the subject invention provide improvements to patient and operator safety, along with ease-of-use and convenience improvements over conventional techniques.

RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 11/838,692filed Aug. 14, 2007, which is a non-provisional application of U.S.Provisional Application No. 60/898,953 filed Feb. 1, 2007. The contentof each of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention is drawn to devices and methods for improvedinjection systems. Variations of the devices and methods of theinjection systems provide atraumatic injection delivery within a spinalcolumn while minimizing the likelihood of causing adverse events.

BACKGROUND OF THE INVENTION

Annually, millions of Americans suffer from significant spine relatedpain and discomfort. Where the cervical, thoracic, and lumbar vertebraeand discs can be the source of this pain and discomfort. In oneestimate, pain perceived in the neck or upper limbs that is caused byirritation in the nerves that exit the cervical spine through theforamen affects a population of approximately 1 person per 1000 peryear. As a result, every year physicians in the United States perform anestimated 750,000 transforaminal cervical injections to treat thesepatients.

While the nerve irritation and resultant inflammation causing thisspinal pain has a variety of etiologies that result in contact betweenthe nerve and the adjacent structures in the spine, transforaminalinjections of corticosteroids can relieve this irritation and reduce theaccompanying pain.

Injections of corticosteroids and or local anesthetics into isolatedareas of the epidural space are important treatment and diagnosticmodalities for patients suffering from spinal pain syndromes. Isolationof the injection to a specific spinal level is accomplished by using atransforaminal approach. This is distinguishable from the traditionaltrans-laminar approach of spinal epidural injections commonly used foranesthesia.

Presently, physiatrists, anesthesiologists, radiologists, neurologists,and orthopedic surgeons perform such transforaminal injections underfluoroscopic guidance using a C-Arm fluoroscope, a standard spinalneedle, and three 3 cc syringes. One current technique in providingthese injections includes conscious sedation of the patient through theuse of local anesthetic and anxiolytics. The operator performs theprocedure using multi-plane fluoroscopy to guide the needle intoposition and to verify correct location of the delivery device prior toinjection of the substance.

As shown in FIG. 1A, existing delivery devices include a 20-25 gaugehypodermic needle 1 that is inserted through the skin, muscle and softtissues 10. Using fluoroscopy, the operator positions the distal end ofthe needle immediately adjacent to a portion of a vertebral body 12 atthe level of the desired injection. Typically when delivering theinjection in a cervical region of the spine, this includes positioningthe tip of the needle immediately adjacent to a posterior inferioraspect of a superior articular process 14 of a facet joint of thevertebral body 12 at an index foraminal level chosen for the injection.Care must be taken to avoid puncturing the vertebral arteries or veins16 extending through foramens in the vertebral body 12.

To test the initial placement of the needle it is standard for theoperator to initially inject a contrast media, such as a radio opaquedye. This step is useful to determine whether the needle is undesirablylocated in a blood vessel 16 or in the dural membrane 18. To verifywhether the needle is desirably placed, the operator observes underfluoroscope for negative indication of veneous, arterial, orcerebrospinal uptake of the dye. Upon confirming the correct location,the needle is left in position while the syringe containing the radioopaque dye is carefully removed from the needle and replaced by asyringe containing a local anesthetic such as lidocaine. As explainedbelow, the operator must take great care not to avoid any inadvertentmovement or advancement of the needle especially during exchange of thesyringes.

The operator then injects a small bolus of lidocaine (or a localanesthetic of choice) and waits a sufficient period (e.g., sixtyseconds).to allow for the anesthetic to disperse. During this time theoperator observes the patient for adverse reactions resulting fromaccidental vascular uptake or injection into the dural sleeve or thecalsac. Although placement of the needle was observed using the radiopaquedye, there is still a risk of accidental vascular injections because theneedle may have moved during the syringe exchange process or simplybecause vascular perforation was not detected during the radiopaque dyeinjection.

Once the operator confirms negative adverse reactions, the operatoragain carefully exchanges syringes to connect a syringe containing acorticosteroid. Finally, the corticosteroid is injected in an effort toreduce inflammation thereby affording the patient pain relief. After thethree injections i.e. radio-opaque dye, local anesthetic, corticosteroidare complete, the needle is removed from the patient.

Although the current procedure provides benefits to patients havingspinal related pain, significant risk remains with the currentprocedure. One inherent risk includes breaching a blood vessel and theinadvertent injection of dye, anesthetic, and/or corticosteroids into anartery or vein. Currently, it is believed that breaching a blood vesseloccurs in a considerable number of injections performed (a recentclinical study had venous uptake in over 19% of injections performed).Additional risks include contact between the injection needle and thenerve root, which may cause pain along with damage to the dura. Finally,there are risks associated to the operator via exposure to the X-Rayradiation of the fluoroscope, particularly in view of the cumulativeexposure as the operator must position the needle as well as exchangesyringes a number of times.

The actual breaching of the blood vessel may occur during the initialinsertion of the needle into the site, subsequent manipulation of theneedle during syringe exchanges, or even movement of the needle as aresult of the force applied by the operator during actuation of thesyringe. In some cases, injection into a blood vessel may occur even ifthe needle has not penetrated the vessel wall as the force of theinjectant flowing out of the distal tip of the needle can be sufficientcause the injectant to breach the blood vessel wall and enter into thevessel.

Complications from accidental injection of the anesthetic into thevessel can include transient paralysis of the spinal cord. Complicationsresulting from accidental injections of corticosteroids into bloodvessels can include permanent paralysis, permanent blindness (ifinjected into a vertebral artery), seizures, permanent cognitivedysfunction, physical impairment, and/or death.

Another complication associated with transforaminal injections isinadvertent contact between the needle and nerve root which may causepain or tingling emanating through the upper extremities. If the needleperforates the dural sleeve, spinal fluid may leak resulting in atransient headache lasting from several hours to several days. If localanesthetic is injected into the thecal sac, temporary paralysis mayoccur that could result in a cessation of breathing, necessitatingemergency intubation of the patient.

In view of the above risks, to ensure patient safety the operator mustreposition the needle if he or she suspects that patient harm couldoccur. In addition, if arterial uptake is suspected, a commonrecommendation is that the procedure should be abandoned to allow thearterial perforation to heal and to obviate the risk of injury to thespinal cord resulting from inadvertent injection of corticosteroid intothe radicular artery or vertebral artery.

Each time the needle is repositioned, a new X-Ray image must be capturedto verify the needle position and additional real time fluoroscopyimages must be captured with an additional injection of contrast media.The additional fluoroscopy and associated radiation exposure presents anincreased risk to the operator performing the procedure. To minimizeexposure the operator must step toward and away from the radiation fieldto alternately maneuver or manipulate the hypodermic syringe and allowfluoroscopic images to be taken. This exertion combined with therepeated connecting and disconnecting of syringes contributes tooperator fatigue, which is not a trivial consideration for operatorsperforming multiple procedures in a particular day.

The design of the current devices presents an additional problem thatcontributes to undesired device placement. Current devices include rigidand straight hypodermic needles. Such a configuration limits theoperator to only work within the “line of sight” from the surface of theskin along an axis of the needle. In many cases, it is desirable toperform the injection in a position that is not directly accessible by astraight, rigid needle, e.g., it is frequently desirable to injectmedicine in a position “behind” portions of the vertebra, nerves, orblood vessels, (i.e. around the corner from the line of sight position).

Devices and methods are provided herein for a transforaminal epiduralinjection needle system that minimizes the above risks to improvepatient safety. In addition, the benefits of such devices reduceoperator fatigue and decrease the operator's potential radiationexposure.

The methods and devices may be used for transforaminal selectiveepidural injections to the cervical, thoracic, or lumbar spine.Fluoroscopically guided, contrast-enhanced transforaminal epiduralinjection procedures help to specifically evaluate and treat the precisespinal nerve involved as a source of spinal and referred extremity pain.Although therapeutic and diagnostic transforaminal epidural injectionshave been performed for decades, the equipment used for these injectionshas been relatively unchanged during that time.

SUMMARY OF THE INVENTION

The present invention incorporates features that address each of therisks listed above. The devices and methods described herein include acatheter with a blunt distal tip and an injection port that allow drugsor other substances to disperse at a target site while minimizing safetyconcerns. The construction of the catheter decreases the chances ofinadvertently injecting substances into a blood vessel as well asinadvertently damaging structures because of incorrect placement of aneedle.

The invention includes an injection system comprising a needle cannulahaving a sharp tip at a far end of the needle cannula, where the sharptip is adapted to penetrate tissue, and a needle lumen extending throughneedle cannula. The device includes a sliding member slidably affixedwithin the needle lumen to move between a retracted position and adeployed position within the needle lumen. This sliding member may be aplunger, a stop surface, or any such structure. In additionalvariations, the sliding member can be non-rotational (e.g., such ashaving a groove or keyway) so that the injection tube injection port isalways oriented relative to the cannula. In yet another variation, thesliding member can provide information relating to the orientation ofthe catheter tubing to the physician via markings, etc. An injectiontubing having a distal portion having a distal end, a proximal portion,and an injection lumen extending between the distal portion and theproximal portion, where the injection lumen exits the injection tubingat an injection port located in a sidewall in the distal portion; wherethe injection tubing is affixed to the sliding member such that when thesliding member is in the proximal position, the distal portion is withinthe needle cannula and when the sliding member advances to the deployedposition, the distal portion of the injection tubing extends out of thefar end of the needle cannula. Given that the sliding member is affixedto the injection tubing, the injection tubing can be moved a limiteddistance by advancement or retraction of the sliding assembly. Thebenefits of such a feature are described below. An embodiment of thesystem also includes a plurality of independent extension tube lumenswhere a manifold fluidly couples each of the extension tube lumens tothe injection lumen.

The invention further includes methods of delivering substances into anepidural space using one of the variations of the devices described. Inone variation the invention includes methods of delivering substancesinto a spine, epidural space, spinal canal or similar region of thebody.

In one variation, the methods include a needle cannula having a needlelumen and an injection tubing extending through the needle lumen, wherethe injection tubing comprises an injection lumen, fluidly coupling asource of a radiopaque material to the injection lumen and independentlyfluidly coupling a source of a first therapeutic substance to theinjection lumen, where such coupling occurs prior to inserting theneedle cannula into the patient, inserting a distal end of the needlecannula so that it is spaced a distance from the epidural space,advancing the injection tubing through the needle cannula to advance atip of the injection tubing from the distal end of the needle cannula tothe epidural space, delivering the radiopaque material through theinjection lumen to the epidural space to verify placement of the tip ofthe injection tubing, and delivering the first therapeutic substancethrough the injection lumen to the epidural space without disconnectingthe source of the radiopaque material from the needle lumen.

In yet another variation, the method includes providing an injectionsystem including a needle cannula having a needle lumen extendingtherethrough and an injection tubing having a curved shape at a distalportion, where the injection tube is slidably located in the needlelumen to move between a retracted position and a deployed position,where in the retracted position the injection tubing remains within theneedle lumen and in the deployed position, the injection tubing extendsout of a far end of the needle cannula to curve away from an axis of theneedle cannula, advancing a tip of the needle cannula into the patientso that the tip is positioned adjacent to the vertebral body and spaceda distance from the foramen of the vertebral body, advancing the distalend of the injection tube around a feature of the vertebral body , intothe foramen by advancing the injection tube within the needle cannulasuch that the distal portion exits the injection tube and assumes thecurved shape.

The injection system may deliver injectants, injectable substances,and/or injectable fluids. Such substances are intended to include anymedication or diagnostic fluid the physician (or operator) may choose toadminister with the system.

It is noted that the invention includes combinations of embodiments oraspects of the embodiments themselves. The following illustrations areintended to convey an overall concept of the inventive methods anddevices.

This application is also related to commonly assigned U.S. applicationSer. No. 11/838,675 entitled Methods and Devices for Treating Tissuefiled Aug. 14, 2007 (Attorney Docket No. LRMD-N-Z001.00-US). The contentof which is incorporated herein by reference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the detailed description when readin conjunction with the accompanying drawings. It is emphasized that,according to common practice, the various features of the drawings arenot to-scale. On the contrary, the dimensions of the various featuresare arbitrarily expanded or reduced for clarity. Included in thedrawings are the following figures:

FIG. 1 illustrates a previously known procedure for injecting asubstance within a spinal canal of a patient.

FIG. 2A shows a cross sectional view of an example an injection systemincorporating the concepts discussed herein.

FIG. 2B shows a cross sectional view of the injection system of FIG. 2Awhere the catheter or injection tube is withdrawn into the needlecannula.

FIG. 2C shows a cross sectional view of another variation of aninjection system without a plunger mechanism.

FIG. 2D shows a cross sectional view of the injection system of FIG. 2Cwhere the catheter or injection tube is advanced out of the needlecannula.

FIGS. 3A to 3B illustrate an example of placing and deploying theinjection systems according to the devices and methods described herein.

FIGS. 4A to 4D show additional variations of injection systems where amanifold is located on a body of the device.

DESCRIPTION OF THE INVENTION

FIG. 1A illustrates a variation of an injection system 100. Although thesystems and methods described herein are often described as being usedas a cervical injection system or for the cervical region of the spine,the device and methods may be applied in a broader and to various otherparts of the spine as well as anatomic structures where the features ofthe system may provide useful.

As shown in FIG. 1A, the system 100 includes a cannula or needle cannula102 where a distal tip 104 of the needle cannula 102 is sharp so that anoperator may advance the cannula 102 through tissue to reach theintended target site. The needle cannula 102 may optionally include ahub 106. The hub 106 may be a common polymeric hub that is molded,bonded, or otherwise affixed to the needle cannula 102. Alternatively,though not shown, the hub 106 may comprise a section of the needlecannula 102 itself. In any case, in some variations of the system 100,the hub 106 provides an ergonomic surface for the operator to gripduring insertion and potentially manipulate with a single hand. Theshape of the hub (and device body as described in additional variationsbelow) should enable the operator to hold the hub and/or device betweentheir thumb and forefinger of each hand. This improves the operator'sability to aim and guide the needle (and ultimately thecatheter/injection tubing) into position. Additionally, this designshape allows the operator excellent tactile feedback during insertion ofthe device and advancement of the injection tubing.

In one example, when the system 100 is optimized for use in deliveringinjections in the spinal area, the needle cannula can be any standardneedle. In spinal applications the cannula can be 19 to 26 gauge. In onevariation useful for cervical region treatment, a 22 Ga needle having alength of 2.5 inches was developed. However, alternative variations ofthe invention include needles of varying lengths, gauges, as well ascross-sectional shape. As shown, the needle cannula 102 extends onlypartially into the hub 106. However, variations also include a needlecannula 102 that extends through the hub 106.

In any case, the needle cannula 102 includes a needle lumen 108 throughwhich a catheter or injection tubing 110 extends. Although notillustrated, the injection tubing 110 includes an injection lumenextending therethrough and exiting at an injection port 112 in a wall ata distal portion 114 of the injection tubing 110. In additionalvariations, the device can include an injection port at a distal end ofthe injection tubing 110. In addition, variations of devices disclosedherein can include more than one injection port.

The injection tubing 110 can be made of a flexible material such as anypolymeric or composite material used for medical device applications. Inaddition, the catheter tubing can have elastic characteristics (e.g.,flexible polymers, coil or other reinforced catheters, orsuper-elastic/shape memory characteristics), that allow the device tocurve slightly around or deflect away from structures such as bloodvessels, nerves, or bone to optimally position the orifice for theinjections. The elastic characteristics may come from the properties ofthe tube, an elastic wire that is extruded within the wall of the tube,or even an elastic stylus that temporarily resides in the lumen of thetubing. In some variations of the system, the curve of the distalportion of the catheter tubing also enables the operator to “steer” thecatheter by orienting the distal tip such that the catheter tends tofollow a particular direction.

Placing the injection port 112 in a side wall and not at a distal end120 prevents the likelihood that fluid ejected from the device 100 willcause inadvertent damage to the patient. For example, even if a distaltip 120 of the system 100 pierces a vessel or the dura, then theproximal spacing of the injection port 112 reduces the likelihood thatthe injected fluid would actually enter the structure as the fluid willbe injected proximal to the entry point. In other words, it would benecessary for the entire distal portion 114 of the injection tubing 110(from the injection port 112 to the distal tip 120 to cannulate thevessel or dura. In the variation shown, the injection tubing 110 alsoincludes one or more visualization marker(s) 127. For example, a singleradiopaque marker 127 can be placed adjacent to the injection port 112so that the operator may precisely locate the proximity of the injectionport 112 to a vessel or other structure. Yet another feature thatimproves safety is placement of the injection port 112 on an interiorradius or aspect of the curved distal portion 114 of the injectiontubing 110. As fluid disperses from the injection port 112, because theinjection port 112 is on the interior curve of the distal portion 114 ofthe injection tubing 110, the fluid is delivered away from the dura orother nerve structures (as will be discussed below). However, additionalvariations of the invention contemplate placing an injection port 112anywhere along the distal portion of the injection tubing 110.

Systems 100 of the present invention also include a sliding member, inthis variation the sliding member is a plunger 122 slidably affixedwithin a lumen of the needle cannula 102 and secured to the injectiontubing 110. This construction permits movement of the plunger 122 toadvance or retract the injection tubing 110. Since the plunger 122 isslidably affixed within the needle cannula 102, the plunger 122 can movebetween a proximal or retracted position (where the distal portion 114of the injection tubing is retracted within the needle cannula) and adistal or deployed position (where the distal portion 114 of theinjection tubing 110 is deployed from the needle cannula 102 as shown inFIG. 2A).

FIG. 2B illustrates a distal section of the system 100 showing theplunger 122 in a retracted position causing the distal portion 114 ofthe injection tubing 110 as well as the injection port 112 withdrawninto the cannula 102. As discussed below, configuring the injectiontubing 110 to advance in and out of the cannula 102 improves the abilityof the operator to safely locate the tip 104 of the cannula 102 whileadvancing the injection tubing 110 and port 112 to a desired locationfor delivery of the substances. This feature of the system 100 isdiscussed in further detail below. Alternate variations of the inventioncan include plungers that are removeable from the needle cannula 102.The plunger 122 may comprise a simple tube structure. In some variationsof the system 100, the fit between the injection tubing 110 and needlecannula 102 allows a tactile “feel” of the resistance as the catheter isadvanced to the injection site. This feature helps the operator feelwhether the tip of the device encounters any structures as it advancesto the target site.

In the variation shown in FIG. 2A a proximal portion 116 of theinjection tubing 110 extends from the plunger 122 to a manifold 126. Themanifold 126 allows fluid coupling of any number of extension tubes 128having separate lumens to the lumen of the injection tubing 110.Although the variation shows three separate extension tubes 128,variations of the device may include a single extension tube with aplurality of independent lumens. The independent lumens should allowcoupling of the system 100 to independent fluid sources 50 (typicallysyringes or other such storage vessels). The number of lumens may be anynumber greater than 1. However, when the system 100 is used fortreatment of spinal conditions, the system 100 will typically includethree separate extension lumens so that three separate fluid sources(e.g., a source of a contrast agent, a source of an anesthetic, and asource of an anti-inflammatory substance such as a corticosteroid). Asshown, the extension tube 128 can include a luer or other fitting 130 onthe proximal end to allow coupling to a fluid source. Moreover,variations of the device include use of a valve fitting 130 to preventretrograde flow between syringes.

One advantage of having separate lumens for coupling syringes or fluidsources is to maintain segregation between the injectable substances.The use of multiple tube lumens reduces the amount of residualsubstances that must clear the device during subsequent injections. Thisreduces risk of injecting the patient with an excessive amount of anysubstance or inadvertent injection of an incorrect substance.

In certain variations of the system 100, the length from the plunger 122to the fittings 130 is sufficient so that fluid sources (e.g., syringes)can be coupled to the system 100 and set aside prior to insertion of theneedle cannula 102 into a patient. In addition, a sufficient lengthallows the operator to inject the fluids without excessive exposure toradiation generated by x-ray or fluoroscopic equipment. Although notshown, variations of the system 100 include the use of strain reliefsleeves or collars to prevent crimping or folding of the injectiontubing 110 at or near the end of the plunger 122.

The operator prepares the system 100 for the procedure by attachingthree syringes to the device simultaneously prior to insertion into thepatient. Naturally, an operator may choose to attach the syringes to thesystem 100 after injection of the cannula into the patient; however,this increases the chance of movement of the cannula subsequent toinitial placement. The injection tubing 110 is advanced distally fromthe tip of the needle (as shown in FIG. 2A) and air is purged from theall of fluid lines by actuating the syringes containing the substancesto be injected (e.g., corticosteroid, anesthetic, and contrast media).Naturally, the injection tube lumen should be charged with the firstsubstance to be injected into the patient.

The individual syringes can contain a contrast agent such as aradio-opaque dye, a local anesthetic such as Lidocaine, and acorticosteroid. Alternatively, any plurality of lumens and extensiontubes could be use in this method were it practical or to the advantageof the operator to have a separate delivery of a plurality of othersubstances/injectants other than those mentioned above.

After the purging and charging sequences are completed, the injectiontubing 110 is retracted into the needle cannula 102 and the operator maynow insert the cannula 102 into a patient to provide treatment.

FIGS. 2C and 2D illustrate another variation of a distal section of thesystem 100 where the sliding member comprises a stop surface 132 that isentirely within the hub 106 of the device 100. FIG. 2C illustrates theplunger 122 in a retracted position causing the distal portion 114 ofthe injection tubing 110 as well as the injection port 112 to bewithdrawn into the cannula 102. As illustrated, the stop surface 132 isaffixed to the injection tubing 110 and is slidably moveable within thehub 106. As shown, when the stop surface 132 is retracted towards aproximal portion 107 of the hub 106, the internal construction of thehub 106 prevents further withdrawal of the injection tubing 110 sincethe stop surface is affixed thereto. As noted above, the stop surface132 can include a key/groove interface with the interior of the hub toprevent rotation of the injection tubing.

FIG. 2D illustrate distal advancement of the stop surface 132 against adistal portion 109 of the hub 106. Again, since the stop surface 132 isaffixed to the injection tubing, distal advancement of the injectiontubing 110 is prevented once the stop surface 132 encounters the hub106. As shown, in the distal most position, the injection tubing extendsfrom the cannula 102 (and optionally curves as shown).

In those variations, where the injection tubing 110 does not include aplunger, the physician simply advances the injection tubing, manifold,or extension lines, to advance a distal portion 114 of the injectiontubing from the cannula 102. As noted above, the variation shown inFIGS. 2C and 2D can include a single injection or extension tube, or mayinclude a number of injection tubes fluidly coupled to a lumen of theinjection tube.

As shown in FIG. 3A, the needle is positioned in the patient underfluoroscopic guidance in the manner described in the conventionalprocedure, with the exception that the distal tip 104 of the cannula ispositioned approximately 5 mm proximal to the intended target site(typically the epidural space or spinal foramen). This position keepsthe sharp tip 104 away from critical vasculature 16 and nerves 20. Asshown, the plunger 122 is in a proximal or retracted position, whichmaintains the distal portion of the injection tube 110 within thecannula 102. The operator can confirm placement of the cannula 102 byinjecting the contrast agent or dye in the manner described above or bysimply observing the cannula 102 under fluoroscopy or x-ray.

The operator can holds the hub 106 and/or the cannula 102 whileadvancing the device through the skin and soft tissue. Once positioningof the cannula is properly determined, the portion of the cannula 102 orthe hub 102 can be secured to the exterior skin or operating table insuch a manner as to stabilize it from penetrating deeper or withdrawingfrom the patient, or moving laterally. A second method of stabilizationmay be an adhesive pad with an integrated clamp that adheres to thepatients' skin and stabilizes the needle relative to the patients' skin.

Once the distal tip 104 of the cannula 102 is in position and clampingor adhesive pads are applied the operator is ready for advancing theinjection tube. As shown in FIG. 3B, the operator advances the plunger122 causing advancement of the injection tube 110 to the target site (inone variation the system 100 allow advancement of the tip 120 of theinjection tube 5 mm to the site). As discussed herein, variations of thedevice include an injection tube 110 having a slight radius or curve ata distal portion 114 that enables advancement of the distal portion 114along a curved path that is biased toward the posterior aspect of theforamen. This curved position keeps the injection tube 110 safely awayfrom the vasculature and the nerve root which reside in the proximity ofthe injection site. Additionally, there is a reduced likelihood that theinjection tube 110 will penetrate vessels if it engages the vesselsduring advancement due to the features of the injection tube 110. Asnoted above, variations of the injection tube includes a blunt tip 120.In addition, variations of the device used in spinal applications shallbe flexible.

The injection port 112 is located away from the distal tip 120 (in oneexample the injection port is spaced 2 mm away from the tip, but anyspacing that places the injection port 112 on the distal portion of thedevice is contemplated.) This feature prevents inadvertent vascularuptake since it would be necessary to cannulate the distal portion ofthe injection tube within the blood vessel over a distance long enoughto envelope the injection port as well. Furthermore, in those variationswhere the injection port is placed on an interior radius or aspect ofthe curved distal portion, fluid delivery occurs towards a portion ofthe vertebral body 12 rather than against a vessel or nerve.

Prior to delivery of the substances, the operator can also observe,under fluoroscope, the position of the distal portion 114 of theinjection tube 110 and even the placement of the injection port 112 byobserving the position of one or more radiopaque markers on the distalportion. As noted above, some variations include placing a radiopaquemark or indicator directly adjacent to the injection port therebyenabling the operator to see the exact position where the injection willoccur.

After verifying the correct position of the injection tube and injectionport, the operator continues in the same sequence as the conventionalprocedure described above. For example, the operator injectsradio-opaque dye into the site to verify the tip of the injection tubingis in the correct location and that a blood vessel was not inadvertentlybreached as evidenced by the uptake of radio-opaque dye into the vessel.Next, an injection of a test dose of local anesthetic such as lidocaineis administered followed by a sixty second waiting period before asecond lidocaine dose and or corticosteroid is injected. The lidocaineis injected first and patient observed to ensure that there has not beenintravascular, especially intra-arterial uptake.

As noted herein, because all three syringes can be attached to thesystem 100, it is not necessary to exchange syringes between injectionsequences. This feature not only improves operator convenience andreduces finger fatigue from the syringe exchange, but more importantly,it improves patient safety by reducing the likelihood of inadvertentcannula movement during syringe exchanges. In addition, placement of thesyringes outside of the surgical field or away from the fluoroscope.Operator safety is further improved because the physician administeringthe injections may perform the injection of contrast media safely awayfrom the injection site while using real time direct fluoroscopy. Thisreduces operator cumulative exposure to X-Ray radiation hazards.

After the injection sequence is completed, the cannula 102 can beremoved from the injection site with or without the injection tube 110retracted into the cannula 102.

The volume of fluid in the common fluid path of the catheter system (thevolume of fluid that remains between the manifold and the injection portof the injection tube), is considered insignificant. In one variation ofa system for cervical injection, this volume is approximately 0.02 mlwhereas the typical injection volume of anesthetic is 0.5 ml (0.4% flushvolume), and the injection volume of steroid is 2.0 ml (0.16% flushvolume). Both of these flush volumes are within the “noise level” ofoperators' ability to administer a measured dose of injectants.Therefore, it is not necessary to flush the common fluid path betweeninjections, (e.g. between radiopaque dye, anesthetic, andcorticosteroid).

Although the examples discussed herein, primarily relate to injectionsystems suited for injections in the cervical region of the spine, thefeatures of the system may be used for spinal treatments in the lumbarand thoracic regions as well.

FIGS. 4A-4D illustrate another variation of a system 100 according tothe concepts of the present disclosure. In this variation, the manifoldis directly coupled to a device body 142.

As shown in FIG. 4A, the components of this variation include a cannulaneedle 102, a catheter or injection tube (not shown in FIG. 4A) coupledto a plunger 122, a device body 140, a manifold 126, extension lines ortubes 128, luer connectors 130. As noted above, in additionalvariations, an internal stop surface located within the hub 106 canreplace the plunger 122.

FIG. 4B illustrates a cross sectional view of the system of 4A. Asshown, the body 140 of the injection system 100 may be cylindrical inshape for ease of manipulation. The manifold 126 can extend from theside of the body 13 to permit the flow of injectables (as discussedabove) from the extension lines 128 into the injection tube 112. Theextension lines 128 may be a single multi-lumen cross-section or maycomprise the plurality of individual tubes shown. As discussed herein,the manifold 126 combines the flow of injectables from a plurality ofsources (e.g., syringes) into a single injection lumen 118 for deliverythrough the injection port 112. Naturally, there will be sealing members144 (such as o-rings) to prevent leakage of fluids from the interior ofthe body 140.

In this variation, the plunger 122 can have any shape, but shall have aportion slidably affixed within the interior of the device body 130. Anupper portion of the plunger 122 extends out of the device body 130allowing for an operator to actuate or slide the injection tubing in andout of the cannula 102. The plunger 122 is affixed to the injectiontubing 110 on its lower end with a lumen extending from the catheter tothe sealed cavity within the lumen of the body cylinder to allow theinjectable fluids to flow from the manifold into the catheter. The upperportion of the plunger 122 that extends out of top of the body 140allows the operator to grip the plunger between their forefinger andthumb, thus providing a tactile “feel” of the resistance as the catheteris advanced to the injection site. However, as noted above, the upperportion of the plunger 122 can simply comprise shrink tubing that coversthe plunger and extends over an inch or so of the injection tubing 110to act as a stress relief. Similar stress relief structure can also beplaced over the tip of the manifold to provide stress relieve thecatheter on that end as well. Injectants, injectable fluids, and soforth are defined as any medication or diagnostic fluid the physicianmay choose to administer with the system.

In many variations of the device, the plunger has a limited stroke. Thislimited stroke allows for a known and finite advancement of the distalportion 114 of the injection tube 110 out of the cannula 102. In thevariation shown, the plunger 122 has a stop on an exterior surface inthe form of a raised surface 124. Alternatively, or in combination, astop surface can be located on the injection tube, or even on theplunger portion that is interior to the hub 106. Naturally, any numberof configurations is contemplated.

A flexible catheter or injection tube 110 resides within the cannulaneedle 102 and has a rounded or blunted tip 120 with an injection portor orifice 112 on the side of the catheter 110 near the distal portion114. As noted above, catheter tubing of the present devices can be madefrom a flexible material those known in medical device applications andmay have shaped memory characteristics that allow it to curve slightlyaround or deflect away from structures such as blood vessels, nerves, orbone to optimally position the orifice for the injections. The shapememory characteristics may come from the plastic properties of thecatheter, an elastic wire that is extruded within the wall of thecatheter, or an elastic stylus that temporarily resides in the lumen ofthe catheter.

Again, the injection tubing 110 includes an injection port 112 locatedon the side of the catheter tubing 110 to further reduce the likelihoodof accidental injections into an artery.

Any of the variations discussed herein may include a clamp-stabilizer asan accessory device that holds the system stable relative to the neck.One embodiment of the clamp-stabilizer includes an adhesive pad thatattaches to the body of the patient at the point of insertion. When theneedle is in place, the clamp is activated to hold the needle stablerelative to the patient.

One embodiment of the clamp-stabilizer includes a structure thatattaches to a datum on the bed or bench where the patient is lying. Theneedle is positioned at the operative site and the clamp is activated tohold the needle steady as long as the patient does not move relative tothe datum.

The flow path of the injectable fluids starts in the syringes attachedto the connector 130. The tubing may be multi-lumen tubing or individualtubes. The fluid flows from the syringes through their respectiveindividual lumens in the tubing and into the manifold on the side of thedevice body. The fluids then flow into interior cavity of the devicebody, into the plunger body, through the catheter and out the injectionport on the side of the catheter near its distal end. An alternatevariation includes a piece of tubing that connects the manifold directlyto the proximal end of the catheter tubing thereby bypassing theinterior of the device body.

As noted above and as shown 4C and 4D the system 100 may optionallyinclude a stylus 142. The stylus 142 is can be incorporated into theinjection tube 110 to aid in steering a tip of the injection tube 110 toa desired region. In an alternate variation, the system 100 includes astylus that extends from inside the distal tip of the catheter tubingthrough the lumen of the catheter, through the body of the cylinder andexits the device through a membrane seal on the proximal surface of theplunger. The stylus is used by the operator to push the catheter out ofthe distal tip of the primary needle and into the injection site. Thestylus could optionally have a curvature that translates its' curvatureto the catheter to help steer the tip of the catheter along a curvedpath and into a position that is not accessible by a straight, rigidneedle.

When the catheter tube is in position at the injection site, the styluswould be removed from the catheter to allow the injectants to flowthrough the catheter. The stylus may be supplied in a variety ofcurvatures to allow the operator to select the appropriate curvature tosteer the catheter into position based on variations in anatomy orvarious injection modalities. Alternatively, the stylus may beconstructed of a malleable material that allows the operator to shapethe stylus to a custom curvature.

An alternate device embodiment would include a balloon on the tip of thecatheter. The balloon would be inflated via a lumen in the catheter andwould be used to anchor the catheter in place, dissect tissue, or steerthe catheter by positioning the balloon on one side of the catheter suchthat it pushes the orifice of the catheter toward a particular injectionsite.

Before the present devices and method of treatment are described, it isto be understood that this invention is not limited to particularembodiments described, as such may, of course, vary. It is also to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting, since the scope of the present invention will be limited onlyby the appended claims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimits of that range is also specifically disclosed. Each smaller rangebetween any stated value or intervening value in a stated range and anyother stated or intervening value in that stated range is encompassedwithin the invention. The upper and lower limits of these smaller rangesmay independently be included or excluded in the range, and each rangewhere either, neither or both limits are included in the smaller rangesis also encompassed within the invention, subject to any specificallyexcluded limit in the stated range. Where the stated range includes oneor both of the limits, ranges excluding either or both of those includedlimits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, some potential andpreferred methods and materials are now described. All publicationsmentioned herein are incorporated herein by reference to disclose anddescribe the methods and/or materials in connection with which thepublications are cited. It is understood that the present disclosuresupercedes any disclosure of an incorporated publication to the extentthere is a contradiction.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise. Thus, for example, reference to “anaerosol” includes a plurality of such aerosols and reference to “thedrug” includes reference to one or more drugs and equivalents thereofknown to those skilled in the art, and so forth.

The publications discussed herein are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as an admission that the present invention isnot entitled to antedate such publication by virtue of prior invention.Further, the dates of publication provided may be different from theactual publication dates which may need to be independently confirmed.

1. A method of delivering substances into an injection site in anepidural space of a patient while keeping sharp surfaces away fromcritical vasculature and nerves in the epidural space, the methodcomprising: providing a needle cannula having a sharp distal tip and aneedle lumen exiting at the sharp distal tip, with an injection tubingadvanceable out of the needle lumen, where the injection tubingcomprises an injection lumen; fluidly coupling a fluid source having afluid material to the injection lumen; inserting a distal end of theneedle cannula into the patient and towards an epidural space;positioning the sharp distal tip of the needle cannula proximal to theepidural space to keep the sharp distal tip away from criticalvasculature and nerves in the epidural space; advancing the injectiontubing through the needle cannula to advance a tip of the injectiontubing from the sharp distal tip of the needle cannula to the injectionsite into the epidural space; delivering the fluid material through theinjection lumen.
 2. The method of claim 1, where advancing the tip ofthe needle cannula into the patient comprises advancing the tip of theneedle cannula through a vertebral foramen.
 3. The method of claim 2,further comprising fluidly coupling a plurality of fluid sources to aninjection lumen in the injection tubing prior to advancing the tip ofthe needle cannula into the patient.
 4. The method of claim 3, wherefluidly coupling the plurality of fluid sources comprises placing thefluid sources away from the immediate vicinity of the patient.
 5. Themethod of claim 3, further comprising sequentially delivering fluid ineach fluid source through the injection tubing without de-coupling therespective fluid source from the injection lumen.
 6. The method of claim3, where the plurality of fluid sources each comprises at least aradiopaque substance, an anesthetic, and an anti-inflammatory substance.7. The method of claim 1, where the injection tubing is coupled to aplunger member having a limited range of movement within the needlecannula, where advancing the tip of the distal end of the injectiontubing comprises advancing the plunger member within the needle cannula.8. The method of claim 1, where advancing the tip of the needle cannulainto the patient so that the tip is positioned adjacent to the vertebralbody comprises spacing the tip of the needle cannula from the vertebralforamen of the patient.
 9. A method of delivering substances into aninjection site in an epidural space of a patient while keeping sharpsurfaces away from critical vasculature and nerves in the epiduralspace, the method comprising: providing a needle cannula having a sharpdistal tip and a needle lumen exiting at the sharp distal tip, with aninjection tubing advanceable out of the needle lumen, where theinjection tubing comprises an injection lumen and where the injectiontubing comprises elastic characteristics; ; fluidly coupling a fluidsource having a fluid material to the injection lumen; inserting adistal end of the needle cannula into the patient and towards anepidural space; positioning the sharp distal tip of the needle cannulaproximal to the epidural space to keep the sharp distal tip away fromcritical vasculature and nerves in the epidural space; advancing theinjection tubing through the needle cannula to advance a tip of theinjection tubing from the sharp distal tip of the needle cannula to theinjection site into the epidural space where the elastic characteristicsof the injection tubing cause the injection tubing to curve slightlyaround or deflect away from structures; and delivering the fluidmaterial through the injection lumen.
 10. The method of claim 9, whereadvancing the tip of the needle cannula into the patient comprisesadvancing the tip of the needle cannula through a vertebral foramen. 11.The method of claim 10, further comprising fluidly coupling a pluralityof fluid sources to an injection lumen in the injection tubing prior toadvancing the tip of the needle cannula into the patient.
 12. The methodof claim 11, where fluidly coupling the plurality of fluid sourcescomprises placing the fluid sources away from the immediate vicinity ofthe patient.
 13. The method of claim 11, further comprising sequentiallydelivering fluid in each fluid source through the injection tubingwithout de-coupling the respective fluid source from the injectionlumen.
 14. The method of claim 11, where the plurality of fluid sourceseach comprises at least a radiopaque substance, an anesthetic, and ananti-inflammatory substance.
 15. The method of claim 9, where theinjection tubing is coupled to a plunger member having a limited rangeof movement within the needle cannula, where advancing the tip of thedistal end of the injection tubing comprises advancing the plungermember within the needle cannula.
 16. The method of claim 9, whereadvancing the tip of the needle cannula into the patient so that the tipis positioned adjacent to the vertebral body comprises spacing the tipof the needle cannula from the vertebral foramen of the patient.